Trim response header name

[nuryagdym]

Hi,
I working on a library that I am working on supports PSR-18 and PSR-7 implementations.
I tried following PSR-7 libraries:
nyholm/psr7
laminas/laminas-diactoros
slim/psr7

and following PSR-18 clients:
php-http/curl-client
symfony/http-client
guzzlehttp/guzzle

and when I tried combination of all these PSR-7 and PSR-18 libraries.
I faced issue only on symfony/http-client Psr18Client client.
Error is caused when I received response with header name containing leading space " x-xss-protection". This library does not trim response header names that is why all 3 PSR-7 libraries throwing error "Header values must be RFC 7230 compatible strings" when used in combination with symfony/http-client.
The other 2 PSR-18 clients trim header names:

guzzlehttp/guzzle: GuzzleHttp\Handler\CurlFactory::createHeaderFn()

php-http/curl-client: Http\Client\Curl\Client::prepareRequestOptions()

So, I added trim line on Psr18Client, hope it does not break anything, it is working for me at least.

I guess this fix should be done on all maintained versions of this library as well.

PS
I also, tried to trim using Symfony\Component\HttpClient\HttpClientTrait::normalizeHeaders() but it does not do anything about this leading space in the header name.

[symfony-bot]

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